American Association for the Advancement of Science 2009
Fighting the Rising Tide of Antibiotic Resistance: Causes and
Cures in the Sea
Friday February 13 3:30 – 5:00 PM, Chicago, IL
Symposium Organizer and Moderator
Carolyn Sotka,
NOAA's Oceans and Human Health Initiative, Charleston, SC
Senior Science-Policy Analyst
NOAA's Oceans and Human Health Initiative
Hollings Marine Laboratory
331 Fort Johnson Road
Charleston, SC 29412-9110
Phone: 843-817-5971
Fax: 843-762-8737
Symposium Co-Organizer
Paul Sandifer, NOAA's Oceans and Human Health Initiative, Charleston, SC
NOS Senior Scientist for Coastal
Ecology
NOAA's Oceans and Human Health Initiative
Hollings Marine Laboratory
331 Fort Johnson Road
Charleston, SC 29412-9110
Phone: 843-762-8814
Fax: 843-762-8737
paul.sandifer@noaa.gov
Virulent bacteria are winning the arms race against our current arsenal of
antibiotic drugs, posing a significant and growing threat to global public and
ocean health. In the United States, diseases and secondary infections related to
antibiotic resistance are on the rise, difficult to treat, cost in excess of 5 billion
dollars annually and may account for more deaths than from HIV-AIDS,
Parkinson's disease, emphysema or homicide. Research has turned to the ocean
to provide insight about potential causes and cures in this evolutionary battle.
Methicillin-resistant Staphylococcus aureus (MRSA) has been detected and
isolated from coastal waters and beaches, and resistance patterns in bacteria
that commonly cause seafood illness have been discovered. The presence of
these bacteria in coastal environments may increase the exposure of humans to
resistant infections, increase the potential for new, stronger strains to emerge
and prevent common treatment. At the same time, marine natural products
researchers are discovering new ways to potentially render out-of-use antibiotics
effective again, find novel drugs and help fight the resistance war. In this
symposium, an interdisciplinary panel of government, academic and non-profit
scientists will present the latest research on the spreading, strengthening, and
evolution of antibiotic resistance in the ocean, and promising new solutions and
treatments from undersea medicine cabinets.
MRSA’s Silent Threat: What happens at the beach doesn’t always stay at
the beach
Lisa R W Plano1, Anna C Garza1, Helena M Solo-Gabriele1, Cristina Ortega1, Lora E
Fleming1, and Jay M Fleisher2
University of Miami1 and Nova Southeastern University2
Staphylococcus aureus is a common commensal bacterium found colonizing
humans, their pets and thriving in the environment. In addition to peaceful coexistence with humans, these bacteria are capable of causing numerous types of
serious infections when given the opportunity. S. aureus are responsible for
infections ranging from simple infections of the middle ear to those of the blood,
bones and major organs. Adding to the challenges faced in treating
staphylococcal infections; these organisms have acquired resistance to virtually
all antibiotics used against them. Infections with S. aureus, and especially the
multi-drug resistant MRSA, have become responsible for huge healthcare costs
and are projected to be responsible for more deaths this year than HIV/Aids. The
serious health threat posed by S. aureus is not limited to the hospitals or
healthcare setting as acquired infections from community sources are emerging
as a significant threat. In fact, infections by MRSA are now the most common
cause of skin and soft tissue ailments in people who go to the nation’s
emergency rooms for care. As infections with these organisms increase, the
search for all the sites or sources where they may survive and be shared among
individuals is paramount. By determining the locations where the bacteria are
harbored and the factors that may contribute to spreading these bacteria, plans
can be devised to decrease the spread and therefore the risk. Our studies
investigate a popular marine recreational beach as a potential reservoir for
MRSA to be shared by those individuals using these waters. Our hypothesis is
that the bathers using recreational waters not only contribute to the organisms in
the water, and therefore serve as a source of pathogens, but might also become
colonized or infected by the organisms that they are exposed to while in the
water or on the beaches. In the first large epidemiology study investigating
potential pathogens at a beach not impacted by sanitary sewage discharges,
1303 adult habitual bathers were randomly assigned to bather or non-bather
groups, with subsequent follow-up for reported illness and environmental
sampling of indicator organisms and potential pathogens. S. aureus, including
MRSA, were isolated from the water associated with 37% (2.7% MRSA) of the
bathers during recreational use. Additional studies using marine waters in small
and large pool settings confirmed that bathers, both adults and young children in
diapers, were a source of S. aureus and MRSA isolated from the study waters
and sand samples. These findings support our hypothesis and demonstrate that
human health risks occur in non-point source recreational marine beaches.
Lisa R. W. Plano, M.D., Ph.D.
Associate Professor
Departments of Pediatrics, Microbiology & Immunology and Dermatology
Leonard M. Miller School of Medicine
University of Miami
1600 NW 10Th Ave
Miami, Fl 33136
(305) 243-2598 office
(305) 243-4623 fax
chroma.med.miami.edu/micro/faculty_plano_l.html
lplano@miami.edu
Uncovering Patterns of Antibiotic Resistance in Seafood-borne Pathogens
Abstract: The spread of antibiotic resistance (AR) among pathogenic
microorganisms is a major public health concern and a striking example of
evolution in action. What remains largely unknown is the environmental origins of
AR and the natural and human-induced controls of AR in the environment. Many
microbial genes responsible for AR are millions of years old. They became a
public health concern only recently, after the introduction of antibiotics to treat
human and livestock pathogens. The use and abuse of antibiotics has resulted in
a dramatic selection for and subsequent proliferation of pathogens carrying
antibiotic resistance genes. Other chemical agents, including toxic metals, may
also be indirectly involved in the selection for AR, through genetic linkages of
multiple resistance factors. Some AR genes are located on mobile genetic
elements, enabling their transfer among various microbial species.
In the largest survey of its kind, we found that resistances to all major
classes of antibiotics are prevalent in Vibrio vulnificus, V. parahaemolyticus, and
E. coli along the southeastern U.S. Atlantic coast. Numerous Vibrios were
resistant to antibiotics routinely prescribed to treat their infections, including
tetracyclines, aminoglycosides, and cephalosporins. V. vulnificus causes 95% of
all seafood poisoning-related deaths in the U.S. The fatality rate approaches
100% if not appropriately treated within 72 hours. Our results emphasize the
significance of environmental AR studies and may lead to improved treatment of
seafood-borne infections.
We demonstrated that industrial effluents containing toxic metals may
induce selection for AR in freshwater environments. We did not observe the
same effects in marine environments, e.g. the frequency of AR in Vibrios was
similar in pristine and metal-contaminated coastal areas. This is likely due to
lower metal toxicity in seawater relative to freshwater. However, water and
sediment samples collected near urban centers contained E. coli with elevated
AR, indicating prolonged survival of resistant strains originating from municipal
effluents. We obtained the complete genome of one multi-resistant E. coli strain
with extreme AR. The genome sequence revealed multiple cellular mechanisms
governing AR, including novel genes as well as genes encoded on mobile
genetic elements. The genetic signature of this bacterium suggests that it was
transported into the study area by migrating birds. Our results demonstrate the
importance of complex ecosystem processes in the proliferation of AR in
opportunistic human pathogens in the environment.
Ramunas Stepanauskas
Senior Research Scientist
Bigelow Laboratory for Ocean Sciences
P.O. Box 475
West Boothbay Harbor, Maine 04575-0475
Phone: 207-633-9600
Mobile: 207 380 4688
Fax: 207-633-9641
e-mail: rstepanauskas@bigelow.org
homepage: http://www.bigelow.org/srs/stepanauskas.html
Breaking the Barrier: Discovery of Anti-Resistance Factors and Novel
Ocean Drugs
Abstract: National Oceanic and Atmospheric Administration (NOAA)’s
investigations into coral disease, red tides and other marine environmental
issues have led to discoveries of novel chemicals as a source for new
pharmaceuticals. A class of these chemicals function as antibiotics for
microorganisms providing survival advantages and may be applied for use in
human health care. Our research has found several compounds such as
euglenophycin, recently isolated and characterized from Euglena sanguinea (a
freshwater and estuarine microbe) which exhibits very strong antibiotic,
antifungal, and antiviral potential as well as some anti-cancer and angiogenesis
activities. Also, our research into coral disease has resulted in thousands of new
bacterial isolates producing highly selective antimicrobial compounds such as in
the Gorgonian coral Pseudopterogoria americana that yields highly selective
small peptide antibiotics. Many of these novel anti-biotics are advantageous, as
they demonstrate no cytotoxic responses to human cells and may minimize
negative side effects associated with those drugs in current usage. Observations
from the sponge Agelas conifera’s ability to protect itself against fouling and
disease led to the discovery of ageliferin isolates that demonstrate very strong
anti-biofilm activity. The compounds with this specific activity hold promise to
increase the efficacy of current and out of use antibiotics with their ability to
inhibit and/or disperse the protective layer that infectious agents often produce to
protect themselves. Such compounds are also finding potential use in other
areas of human health as well, including cystic fibrosis, chemo-therapy, antifungal agents, and for use in medical stints and prosthetics. Marine natural
products hold much promise in combating both the trend of antibiotic resistance
but also to discover new antibiotics. The one-two punch of discovering new
antibiotics as well as novel chemicals that make older generation drugs more
effective represents cutting edge science addressing a critical need in human
health care.
Peter Moeller, Ph.D.
Toxin/Natural Products Chemistry Program
National Ocean Service
Center of Excellence for OHH at the
Hollings Marine Laboratory
331 Ft. Johnson Road
Charleston, SC 29412
peter.moeller@noaa.gov
(843) 762-8867
Fax: 843-762-8737